Mica Substrate Chalcopyrite Solar Cell Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Chalcopyrite solar cells using glass substrates face limitations in high-temperature selenization, substrate flexibility, and series resistance due to mechanical scribing, while alternative substrates like polymer film and stainless steel have their own drawbacks such as low heat resistance and risk of short circuits.
Innovation Solution
A chalcopyrite solar cell configuration using a mica substrate with a binder layer, through holes for scribing, and a transparent n-type second electrode layer to avoid substrate scratches and ensure bending rigidity, allowing for flexible and efficient production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If glass substrate is used for chalcopyrite solar cell, then the surface smoothness and availability are improved, but the substrate flexibility and bending rigidity deteriorate
Solution Approach 1:
The patent changes the substrate material parameter from glass to mica, which has different physical properties including higher flexibility and bending rigidity while maintaining the required surface smoothness for film deposition, thus resolving the contradiction between ease of manufacture and substrate flexibility
Solution Approach 2:
The patent uses a composite structure with mica as the substrate and multiple functional layers (binder layer, electrode layers, light-absorbing layer, buffer layer) deposited on it, combining the advantages of mica's flexibility with the functional requirements of solar cell operation
2Productivity
If mechanical scribing is performed to divide the solar cell, then the unit cells are separated, but the substrate is scratched and series resistance increases
Solution Approach 1:
The patent replaces the mechanical scribing process with a chemical etching process using a patterned mask, which divides the solar cell into unit cells without mechanically scratching the substrate, thus maintaining substrate integrity and reducing series resistance while achieving the required unit cell separation
Solution Approach 2:
The patent introduces a patterned mask as an intermediary tool that enables precise division of the solar cell through chemical etching without direct mechanical contact with the substrate, avoiding substrate damage and reducing series resistance between unit cells
3Productivity
If high-temperature selenization is performed to improve energy conversion efficiency, then the precursor selenization is advanced, but the glass substrate cannot withstand the temperature
Solution Approach 1:
The patent changes the substrate material parameter from glass to mica, which has higher temperature tolerance, enabling the precursor selenization to be performed at higher temperatures to advance the selenization process and improve energy conversion efficiency without substrate damage
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The configuration ensures high flexibility and bending rigidity of the solar cell, reduces series resistance, and enables efficient production with improved energy conversion efficiency and reduced production costs.
Implementation Method 1
When the chalcopyrite solar cell 10 is irradiated with light such as solar light, pairs of an electron and a hole are generated in the light absorbing layer 16
Implementation Method 2
the first electrode layer 14 made of Mo is formed by sputtering or the like on the glass substrate 12
Implementation Method 3
an annealing process is performed in an H2Se gas atmosphere. During the annealing process, selenization of the precursor occurs
Data Source
AI summary
A first electrode layer 14 is formed on a mica substrate 54, and then first scribe portions 64 are disposed. Next, a light absorbing layer 16 and a buffer layer 18 are disposed on the first electrode layer 14, and through holes (second scribe portions 66) which penetrate from the upper end face of the buffer layer 18 to the lower end face of the mica substrate 54 are formed in a spot-like manner. Then, a second electrode layer 20 is disposed on the buffer layer 18. At this time, the lower end face of the second electrode layer 20 reaches the first electrode layer 14 along the inner peripheral walls of the second scribe portions 66. Furthermore, the second electrode layer 20 is scribed to dispose third scribe portions 70.